The present invention relates to a novel silicone-based water-repellent agent capable of imparting excellent water-repellency to various kinds of woven fabrics and a method for imparting excellent water-repellency therewith to various kinds of woven fabrics. In particular, the method is useful for the water-repellent treatment of velveteen or the like fabrics with splicing wool in the warps or woofs and the thus treated fabrics nevertheless have good and reliable susceptibility to adhesive bonding of lining cloth and the like by use of a hot-melt adhesive.
As is well known, various kinds of water-repellent agents formulated with silicone materials, i.e., organopolysiloxane compounds, are currently in use for imparting water-repellency to woven and non-woven fabrics. Principal silicone component in most of these silicone-based water-repellent agents in the prior art is a methylhydrogenpolysiloxane and very excellent water-repellency is imparted to the fabrics treated therewith. Unfortunately, fabrics treated with a methylhydrogenpolysiloxane-based water-repellent agent are disadvantageously less susceptible to adhesive bonding of other cloths, in particular, by use of a hot-melt adhesive in addition to the acquisition of undesirable properties of increased stiffness and poor feeling of the treated fabrics. Although such silicone-treated fabrics have no particular problems in working with sewing machines, drawbacks are unavoidable when such silicone-treated fabrics are worked by integrally bonding lining or interlining cloths by use of a hot-melt adhesive with the object to save labor and time, because the once bonded cloth is readily separated from the silicone-treated fabric by the loss of adhesion owing to the releasability inherent to the silicones.
Several attempts have been made in two ways to solve the above mentioned problems in the silicone-treated water-repellent fabrics. First of the approaches is the modification of the hot-melt adhesive used in adhesive bonding of such a silicone-treated fabric. For example, an improved hot-melt adhesive is proposed in Japanese Patent Kokai No. 54-149741 which is a composition comprising a polyolefin resin to which an organosilane compound having a hydrolyzable group along with hydrocarbon groups is graft-copolymerized and a catalyst for the silanol condensation. The hot-melt adhesives of this type have relatively low strength of adhesion and are disadvantageously less resistant against deterioration by dry cleaning.
As the second approach, the fabric, having been treated with a silicone-based water-repellent agent, is subsequently treated with a carbon-functional silane or a silicone-based primer to improve the adhesive strength with a hot-melt adhesive. This method is sometimes effective but causes a problem since specific facilities are required for the priming treatment leading to a considerable increase in the costs for the facilities and for the process steps in addition to a fatal defect of bad feeling of the primer-treated fabrics.